The present invention relates to the four stereoisomers of 1-crotonoyl-2,2,6-trimethylcyclohexane, more particularly to the trans, E and cis, E isomers, which possess unexpected interesting organoleptic properties and which therefore are useful in the preparation of a great variety of perfume compositions.
Although many examples of crotonoyl-trimethylcyclohexenes and -cyclohexadienes are knwon as flavoring and perfume materials in the recent patent literature (as are the methods of their preparation), (e.g., Dutch patent application No. 70,06649; Dutch patent application No. 68,15985; British Pat. No. 1,240,309; Swiss Pat. No. 509,399; Swiss Pat. No. 521,099; Swiss Pat. No. 521,298; E. Demole et al, Helv. Chim, Acta 53, 541 (1970), surprisingly enough there is no mention in the prior art of analogous compounds with a saturated ring system. Careful testing of the four stereoisomers has shown them to be not only totally different from the compounds with an unsaturated ring system, but also strikingly different from each other. This is less surprising than it may seem at first glance; it is known to anybody skilled in the art that the effect on the olfactive properties, as a consequence of hydrogenation of a double bond or differences in the stereo-chemistry of a molecule, cannot be predicted.